A huge amount of carbon dioxide can be safely stored underground in central Alberta, says a study released by the University of Calgary Friday.

Researchers and industry consultants looked at the costs and risks of permanently storing 20 million tonnes annually of carbon dioxide emissions from power plants such as this TransAlta facility in eastern Alberta.Researchers and industry consultants looked at the costs and risks of permanently storing 20 million tonnes annually of carbon dioxide emissions from power plants such as this TransAlta facility in eastern Alberta. (CBC)

The university described its research as the most comprehensive study of large-scale carbon dioxide storage to have all of its findings made fully available to the public.

The study was funded by the government of Alberta and by industry players, including power producer TransAlta. The company will use the information in developing its proposed storage project near Edmonton.

"It's important that studies of geologic storage be publicly available so that people can make independent judgments of the potential long-term risks of this technology," says study leader David Keith, a professor in the university's Schulich School of Engineering.

The Alberta government has funded four proposed projects related to underground carbon dioxide storage out of a $2 billion fund:

  • $745 million for Shell and its partners to capture and store 1.2 million tonnes of carbon dioxide annually, beginning in 2015, from Shell’s Scotford upgrader and expansion near Edmonton.
  • $495 million for a 240-kilometre pipeline proposed by Enhance Energy to transport carbon dioxide from fertilizer producer Agrium’s plant at Redwater near Edmonton to older oilfields in central Alberta with a goal of increasing oil recovery.
  • $285 million for a proposal by Swan Hills Synfuels to inject carbon dioxide into coal seams 1,400 metres underground to produce and extract a synthetic fuel gas known as syngas, which can be used for power generation and for enhanced oil recovery.
  • $436 million earmarked for a project put forward by power producer TransAlta and its partners to capture carbon dioxide at its Keephills Three facility west of Edmonton and inject it into nearby oilfields or have it stored almost three kilometres underground.

The study found that more research — including drilling test wells onsite — is needed before starting commercial-scale storage operations in rock formations deep beneath the Wabamun area in central Alberta. That's where most of the province's coal-fired power plants are located. Carbon capture is already done under the North Sea and in the Algerian desert but this is the first time the storage has been proposed for an inhabited area.

Sixteen researchers and industry consultants spent 16 months looking at the costs and risks of permanently storing 20 million tonnes annually of carbon dioxide over 50 years — a total of one billion tonnes — in a 5,000-square-kilometre area.

One of the key questions regarding carbon storage is whether the buried gas will leak back up to the surface. The study suggested that about half of the gas could be stored without requiring technology on the surface to contain the pressure underground. Researchers calculated that the costs of injecting the gas and storing it are relatively low — about $3 per tonne — but that capturing it at an industrial facility, pressurizing it and transporting it to a storage site would be at least $30 per tonne.

Carbon storage has its opponents. Greenpeace has raised concerns about the amount of energy required, whether the practice will prolong the world's dependence on fossil fuels, and whether it could displace poisonous or corrosive gases or liquids to the earth's surface.